1. Field of the Invention
This invention is directed in general to a detachable power supply apparatus for use with temperature probes, electrical appliances such as frypans, deep fat fryers, cookers and the like, and in particular to a magnetically attachable xe2x80x9cbreak-awayxe2x80x9d power supply apparatus.
2. Description of the Related Art
Detachable power supply devices are well-known. For example, detachable temperature probes with a power supply cord fixedly attached thereto have long been used with a variety of electrical appliances including cookers, fryers, skillets, fondues, woks, corn poppers and the like. Conventional detachable temperature probes typically include a central control housing with a temperature probe extending therefrom, and a power supply cord fastened to and extending from an opposite end thereof. U.S. Pat. Nos. 2,856,489, 2,926,230, and 3,019,320 all disclose detachable thermostatic control devices including a male probe which can be removably attached to an electrical appliance by insertion into a female receiver thereof. The primary advantage of such devices is the ability to separate the probe from the appliance, allowing the appliance to be fully immersed in water for cleaning.
Detachable temperature probes require that continuous, intimate contact be maintained between the male temperature probe and the appliance""s female receiver to accurately control the appliance""s working temperature. For example, current Underwriters Laboratories, Inc.(copyright) (xe2x80x9cULxe2x80x9d) STANDARDS 1083 (33.1) and (33.2) require that a detachable temperature probe attached to an appliance be capable of withstanding a separation force of 35 lbf. (156 N) at any angle for one minute.
The desire for maintaining intimate contact between an appliance and its temperature probe has compromised safety. Each year a substantial number of accidents occur, for example when a small child inadvertently trips over the probe""s power cord and overturns the appliance, or when the power cord is sharply or forcefully disturbed in other ways causing the appliance to tip, overturn, or move in such a way that the contents of the appliance are spilled. Such accidents can result in serious injury, particularly when the appliance contains hot oil, boiling water, or the like. Further, studies have shown that many of these accidents occur when the probe""s power cord is extended and kicked or pulled at a ninety-degree angle (90xc2x0) thereto (e.g. from the side). Of course, these accidents could be prevented or reduced if, upon being kicked, pulled or otherwise forcefully disturbed, the power cord became separated from the probe without disturbing the appliance.
Indeed, UL recently addressed this issue with respect to certain appliances in its STANDARDS 1083 (36A, effective May 30, 2001) which requires that the force required to separate the detachable power supply cord from the appliances covered by the standard shall be at least 5 percent less than the force required to overcome the static friction of the appliance on a surface.
A need thus exists to provide a safe, convenient, reliable detachable power supply apparatus for use with appliances, and particularly for use with temperature probes and the like.
The present invention generally comprises a detachable power supply apparatus for use with an appliance. The apparatus includes a mounting panel which can be attached, for example, to the appliance""s sidewall or handle, or to the rear end of a temperature probe or the like. The mounting panel includes a ferrous contact plate attached to an outer surface thereof. A power supply device includes a socket plug with a magnet subassembly attached at or near an outer surface thereof. The plug may be removably coupled to the mounting panel by positioning the plug outer surface adjacent the mounting panel""s contact plate. The magnet subassembly is designed to allow the plug to withstand a predetermined or preselected pulling force and a predetermined or preselected shearing or lateral force.
The principal objects and advantages of the present invention include: providing an improved detachable power supply apparatus; providing such an apparatus which can be readily attached to and detached from an electric appliance or a temperature probe; providing such an apparatus which allows the temperature probe to maintain intimate contact with the appliance to accurately and reliably control the appliance""s temperature; providing such an apparatus with a power supply plug which can be magnetically coupled to the probe or appliance; providing such an apparatus which increases safe operation of the appliance by allowing the plug to be detached from the probe by the application of a predetermined or preselected lateral or shear force; providing such an apparatus which requires a predetermined or preselected pulling or tensile force to separate the power supply device from the temperature probe; providing such an apparatus that can be varied to accommodate a variety of appliance input power requirements; providing such an apparatus which meets or exceeds UL STANDARDS and applicable federal, state, and local regulations; providing such an apparatus which allows the temperature probes and appliances to meet or exceed UL STANDARDS and applicable federal, state, and local regulations; and providing such an apparatus which is particularly well-suited to its intended purpose.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.